Is it permissible to sell or dispose of a property owned by the state that was purchased under the "Khalo" system for usufruct, based on the doubt that it is not owned by the buyer?

A lease contract is binding on both parties. If the tenant wishes to take "khalaw" (premium) from another potential tenant in exchange for vacating the property, it is not permissible for him to do so if the term of his contract has expired, because he no longer has any right to the property and must hand it over to its owner. However, if the lease term is still ongoing, there is no objection to him taking "khalaw," because it is in exchange for waiving his right to complete the remaining term. Sheikh Saleh Al-Fawzan has issued a fatwa permitting this if the tenant has a remaining term in the premises; otherwise, he is not allowed to refuse to vacate except with the owner's permission.